JAXP system properties are used to specify the XML and XSLT implementations that are used. Resin defaults to using it's own XML parsers and fast XSLT transformer. Other implementations are used with the specification of the appropriate system properties and values.

Examples of using for commonly used alternative XML parsers and XSLT transformers are in separate sections below. The system property configuration tags can be placed at the or the level.

Setting system properties for alternative libraries requires that the implementation classes, usually in a .jar file, are available in the classpath.

The implementation classes are available for a single web application when the jar file(s) are placed in WEB-INF/lib. Since other web-apps do not see these libraries, this allows you to isolate a particular version of a particular implementation for use by the web-app. It is not uncommon for a new version of these jar files to introduce problems with existing code.

If the system-property is being set at the server level, then the jar files containing the implementation classes need to be placed in $RESIN_HOME/lib. This is also a convenient location for placement if you want to avoid putting the libraries in WEB-INF/lib for every web application. Any jars placed in $RESIN_HOME/lib are avaialable for all web applications.